Visitors view a Lincoln monument at Soldiers' National Cemetery, Monday, Nov. 18, 2013, in Gettysburg, Pa. Nov. 19th marks the 150th anniversary of President Abraham Lincoln's short speech that has gone on to symbolize his presidency and explain the sacrifices made by Union and Confederate forces during the U.S. Civil War. (AP Photo/Matt Rourke)

GETTYSBURG, Pa. (AP) — Thousands of people are heading to a small town in southern Pennsylvania Tuesday to commemorate a speech that for 150 years has been a source of national identity.

President Abraham Lincoln’s Gettysburg Address — first delivered here nearly five months after the major battle that left tens of thousands of men, wounded, dead or missing — will be read by a re-enactor Tuesday to mark the anniversary.

Some visitors are honoring both the speech and those who fought in the battle. Tom Stack, 54, of Wilmington, Del., has an ancestor who fought and died at Gettysburg while serving with the 1st Minnesota Volunteer Regiment.

“It was an incredible time, with incredible individuals, on both sides, really,” Stack said.

The short oration, which begins, “Four score and seven years ago,” was not immediately recognized as a towering literary achievement. Just last week The Patriot-News in nearby Harrisburg retracted a dismissive editorial about the speech published by its Civil War-era predecessor, The Harrisburg Patriot & Union. The paper now says it regrets the error of not seeing its “momentous importance, timeless eloquence and lasting significance.”

The ideals expressed in the speech also weren’t necessarily a reflection of reality. Only a few years after the war a separate cemetery for black Civil War veterans was created in Gettysburg because they were “denied burial in the National Cemetery because of segregation policies,” according to a historical marker placed in 2003.

The free Dedication Day event is held annually at Soldiers’ National Cemetery. Last year’s commemoration drew some 9,000 people.

Interior Secretary Sally Jewell and James McPherson, a leading Civil War scholar, are the keynote speakers for the event and Pennsylvania Gov. Tom Corbett will also deliver remarks.

President Barack Obama declined an invitation. Parks officials say Rutherford B. Hayes is the last sitting president to attend a Nov. 19 event in Gettysburg.

Officials with U.S. Citizenship and Immigration Services will swear in 16 new American citizens. The U.S. State Department is bringing about three dozen foreign journalists from New York and Washington.

In a related event, the annual Remembrance Day Parade in Gettysburg will be held Saturday, featuring Union and Confederate re-enactors who will lay wreaths at the portions of the battlefield their units defended.

There have been events at the national military park all year in connection with the battle. An estimated 235,000 people came to Gettysburg this year on or around the battle’s anniversary in early July.

The National Park Service is streaming the ceremony live nationwide to 90,000 colleges, schools, libraries and museums.